Loading boom with adjustable extension arm



S. S- M INTYRE LOADING BOOM WITH ADJUSTABLE EXTENSION ARM Filed Feb. 23,1960 May 1, 1962 2 Sheets-Sheet 1 INVENTOR. 6101451 SJYINTYRE May 1,1962 s. s. MCINTYRE 3,032,207

LOADING BOOM WITH ADJUSTABLE EXTENSION ARM Filed Feb. 23, 1960 2Sheets-Sheet 2 U 1 A INVENTOR. 1|? m [1 43 6/0 YSM /HTYRE 7 90 Q- WI 3MI Mmd" HTToRnEYJ nited States Patent Ofiice 3,9323%? Patented May 1,1962 3,032,207 LOADING BUOM WITH ADJUSTABLE EXTENSIQN ARM Sidney S.McIntyre, Sedro Woolley, Wash., assignor to The Humboldt Company,Seattle, Wash. Filed Feb. 23, 1960, Ser. No. 10,449 6 Claims. (Cl.212-35) This invention relates to improvements in load lifting cranes ofthose kinds or types that are typified by the device of US. Patent#2,895,622, issued to A. E. Sundin on July 21, 1959; such a craneusually being mounted on a mobile vehicle and comprises a rigidly fixed,vertical standard which, at its upper end, mounts a boom for verticaland horizontal swinging and which boom, also, as a characterizingfeature, is equipped at its outer end with an extension lever arm thatmay be swingingly adjusted in a vertical plane between positions of use,at which it is extended outwardly from the boom end and a position ofrest, at which it is folded inwardly and extended along the top side ofthe boom.

It is the principal object of the present invention to provideimprovements in the means associated with the boom for swinging theextension lever are between any of its extended positions and its backfolded position of rest and for holding it at any position between itslimits of swinging adjustment.

More specifically stated, the present invention resides in theutilization of leaf chain belts in conjunction with the piston rod of ahydraulic cylinder for making and holding the adjustments of theextension lever arm.

Further objects of the invention reside in the details of constructionof parts, in their combination and in their mode of operation, as willhereinafter be described.

In accomplishing the above mentioned and other objects of the invention,I have provided the improved details of construction, the preferredforms of which are illustrated in the accompanying drawings, wherein:

FIG. 1 is a rear end elevator of an automotive truck on which a loadingor load lifting crane, embodying the improvements of the presentinvention, has been mounted and showing the boom extension lever arm inits inwardly folded position of rest.

FIG. 2 is a side view of the boom with the extension lever arm adjustedto an extended position of use.

FIG. 3 is an enlarged sectional detail taken on line 3-13 in FIG. 1,showing the standard rotating gear and rac c.

FIG. 4 is an enlarged horizontal section, taken on line 4-4 in FIG. 3.

FIG. 5 is an enlarged sectional view taken through the hinge joint ofthe boom and its extension lever arm.

FIG. 6 is a vertical cross-section, taken on line 66 in FIG. 5.

FIG. 7 is a schematic showing of the valve and hydraulic devices formaking adjustments of the jacks, boom and lever arm.

Referring more in detail to the drawings:

In FIG. 1, the present boom is shown as operatively mounted on amotorized truck comprising a chassis made up of longitudinally extendingopposite side beams 1010 supported at the rear end of the vehicle by andupon a cross-axle 12 that is equipped at its ends with paired wheels1313. Fixed upon the chassis, transversely thereof, and extended equallyto opposite sides to points slightly beyond the line of the wheels 13 isa tubular housing 15 on and by which the boom is mounted, as willpresently be explained. The cylindrical or tubular housing 15 is seatedby and is fixedly secured in saddles 1515' which, in turn, are suitablybolted to the chassis beams Iii-10. At its opposite ends, the tubularhousing 15 is closed by cover plates 1616 which mount verticallyextending jacks 1717 thereon to be used as presently explained.

The present boom is mounted on the tubular housing 15 in the centrallongitudinal line of the truck. It comprises a tubular standard 19which, at its upper end, mounts the present loading boom Ztl thereon.This boom is a metal fabrication, pivotally fixed at its inner end tothe upper end portion of the standard by a horizontal hinge pin 21 forvertical swinging adjustment between its downwardly extended position ofFIG. 1 and the upwardly extended position of FIG. 2. This boom isequipped at its outer end with an extension lever arm 22 which arm ismounted at its inner end by a pivot pin 23 for vertical swingingadjustment from a position of use, or horizontal extension, as in FIG.2, to a position of non-use, as in FIG. 1 at which position it is foldedback along the top side of the lowered boom.

It is to be observed in FIG. 5 that the inner end of the extension leverarm 22 is equipped with an upwardly 0&- set bearing portion 24 receivingthe pin 23 whereby the extension lever is mounted and whereby, when thislever is folded back along the boom, as in FIG. 1, it will be permittedto lie back along the top side of the boom 20'. Both the boom 20 andextension lever arm 22 are of hollow construction as shown, and it isfurther to be noted that the bearing portion 24 is a part of a casting25 that provides a cylindrically rounded outer surface for the arcuatechain guide rails 25x for seating the lever operating leaf chains aspresently explained.

The vertical swinging of the boom 20 is under control of a hydrauliccylinder 30 that is pivoted at its inner end within the upper endportion of the standard 19, as at 31, to extend along and within theunder portion of the boom. This cylinder 30 has an extendable andretractable piston rod 33 fixed pivotally at its outer end, by a pivotpin 34 to the medial portion of the boom 20. Fluid pressure medium isapplied, as presently explained, to the inner end of the cylinder 30 toeffect the upward vertical swinging adjustment of the boom.

The swinging adjustment of the extension lever arm 22 is under controlof a hydraulic cylinder 36 that is contained within and extends alongthe boom. It is pivoted at its inner end to the boom by a pivot pin 37and has an extendable piston rod 38 which at its outer end is attachedas at 39 to the ends of paired leaf chains 40 which extend upwardly andabout the chain guides and are fixed at their other ends, as at 42 inFIGS. 2 and 5, to the casting 25. When the lever arm 22 is in theposition, relative to the boom 20 shown in FIG. 2, and it is desired toswing the lever arm upwardly and to its retracted position, the pistonrod 38 is caused to be extended, and through the chains 4040 to effectthis adjustment. This is possible with the boom positioned either as inFIG. 1 or as in FIG. 2.

It has been shown more particularly in FIGS. 2, 5 and 6, that dualchains 404tl are used and that the extension lever arm 22 as equippedwith the chain guiding rail segments 25x provides progressivelydecreasing leverage for the upward swinging adjustment of the lever arm.The piston rod 38 as shown in FIG. 5, receives the dual chains 404tlalong opposite sides thereof, as the rod is fully extended as in FIGS. 1or 5.

At its outer end the lever arm 22 is equipped with suitable means, suchas that represented at 55 in FIG. 2, for attachment thereto of loadlifting chains or the like. This means 55 may be applied to arm 22 or,as here shown, to an extension 22' that is telescopically extendablefrom arm 22.

The tubular standard 19 which supports the boom 20 is rotatably mountedat its lower end on the housing 15 as shown in FIG. 4, for axial turningabout a vertical post 60 that is fixed rigidly in the housing andextends upwardly therefrom. The standard is equipped with a ring gear62, about its lower end, and this is enclosed by a housing 63.

v Supported horizontally and in intermeshing relationship with gear 62is a rack bar 64 that is contained longitudinally within a hydrauliccylinder 65 as seen in FIGS. 7 and 3. At its ends, the rack bar isformed with pistons 66-66 that are reciprocally fitted in cylinder 65.Adjustment of the rack bar endwise in opposite directions operates torotatably adjust the standard to swing the boom horizontally in oppositedirections.

It has also been shown in FIGS. 1 and 3 that the cylinder 65 has beenfixed upon and extends along the housing 15.

The hydraulic control system for the operation of the various movableparts is as shown schematically in FIG. 7. It is to be understood thatthe cylindrical housing 15 serves as a storage reservoir for a suitablefluid pressure medium. A pump 85 operates to continuously draw pressuremedium from the reservoir through a supply line 86 and deliver it underpressure through a pipe line 87 to all valves of a control valve unitdesignated in its entirety at 88, for delivery, selectively, from thevalves to various points of use. The valve unit mechanism 88 comprisesfive independently operable valves each receiving pressure medium fromthe pump 85 as indicated. These valves are designated, respectively, inFIG. 7, by reference characters a, b, c, d and e. Valves and d aredouble acting. The pipe line 87 serves all valves of the unit 88. Valve0, is connected by pipe lines 90 and 91 with opposite ends of cylinder65 and controls the horizontal swinging adjustments of the boom. Valvesa and e are connected, respectively, to the jacks 17 and 17 by pipelines 92 and 93 to give support to the vehicle chassis when support isneeded. Valve b, connected by pipe line 95 with the lower end ofcylinder 30, controls the vertical swinging of boom 20. Valve d which isdouble acting and is connected by lines 96 and 97 with opposite ends ofcylinder 36 controls the action of this cylinder for its swingingadjustment and support of the extension lever arm 22.

If the boom and its extension lever are in the positions of FIG. 2, theboom may be lowered by adjustment of valve b for outflow of fiuid fromthe lower end of cylinder 30. With such lowering of the boom, the pistonrod 38 of cylinder 36 can be extended under control of valve d to swingthe arm 22 to its back folded position as in FIG. 1. Rotation of thestandard to move the boom to either side of the vehicle is under controlof valve 0. Valves a and e control the jacks 17-17 to level up thechassis or give support thereto.

It has been shown in FIG. 1, that the valve assembly 88 is mounted atone side of the vehicle and that the five valves a, b, c, d, and e areindividually controlled by levers 98 that are fixed on correspondingcross-rods 99 which extend to opposite sides of the vehicle and each ofwhich, at its opposite ends, has actuating levers 160 fixed thereto sothat the control can be effected from either side of the machine.

If the lever arm 22 is in a position lying along the boom 20, as seen inFIG. 1, it can be manually pulled out to a position at which its weightwill efiect its outward and downward swinging movement under control ofvalve d.

The hydraulic cylinder 36 and chains 40-40 are effective in lifting thelever arm 22 in a vertical arc from a substantially horizontal positionas illustrated in FIG. 2 to a substantially vertical position where thecenter of gravity of the arm intersects a line perpendicular to thehorizontal. The continued movement of the arm to overlie the boom maythen be manually controlled with the boom lowered to the positionillustrated in FIG. 1. The return of the arm from folded to extendedposition is first achieved by manually swinging the arm to a positionwhere the center of gravity of the arm intersects a line perpendicularto the horizontal. The hydraulic cylinder 36 and chains 464ii then takeover and support the lowering of arm to a desired position and supportthe arm in such position during the loading or unloading operation.

What I claim as new is:

1. In a loading apparatus of the character described, a boom mounted forvertical swinging at its outer end, an extension lever arm pivotallyattached, at its inner end to the outer end of said boom for verticalswinging adjustment relative to the boom, a retractable and extendablepower means mounted on the boom and a chain connection between saidpower means and said extension lever arm for effecting the swingingadjustment thereof incident to the extending and retraction of the powermeans.

2. In a loading apparatus of the character described, a boom mounted forvertical swinging adjustment, an extension lever arm pivoted at itsinner end to the outer end of said boom for vertical swinging adjustmentrelative thereto, a power cylinder mounted on the boom,

having an extendable and retractable piston rod, a leaf chain connectedat one end to said piston rod and at its other end to said extensionlever arm through which support and swinging adjustment of the lever armis effected by the power cylinder.

3. The loading apparatus of claim 2 wherein said extension lever arm ismounted on the outer end of the boom by a horizontal pivot pin andwherein an arcuate chain guide track is mounted about said pivot pinalong which track said leaf chain is drawn under tension and passed forthe swinging adjustment and support of said lever arm. 4. The loadingapparatus of claim 3 wherein said boom is swingable in a vertical planebetween upwardly and downwardly directed positions, and said extensionlever arm is swingingly mounted at the end of said boom for swingingbetween various angular positions, extended beyond the boom end to aposition folded back and along the top of the boom.

5. The apparatus of claim 3 wherein the radius of the chain guide trackincreases progressively, relative to the pivot axis and wherein saidleaf chain, between its end connections with the piston rod and leverarm lies along and against the track for the swinging adjustment of thelever arm to give increased lifting leverage as the extension leverswings outwardly.

6. In an apparatus of the character described, a boom pivotallysupported to swinging in a vertical plane, and having an upwardly offsetbearing portion at its swinging end, an extension lever arm mounted atits inner end on the outer end of said boom for vertical swinging at itsouter end, a casting fixed to the inner end of said lever arm providinga bearing coacting with that at the end of the boom, and a horizontalpivot pin extended through said coacting bearings for the pivotalmounting of said lever arm; said casting embodying a chain guide track,extended about said pivot pin and progressively increasing in radius, apower cylinder pivoted on the boom having an extendable and retractablepiston rod, and a link chain fixed at its end to the piston rod and tothe lever arm and lying along and upon said chain guide track for theswinging adjustment and support of said lever arm.

References Cited in the file of this patent UNITED STATES PATENTS2,639,826 Welden May 26, 1953 2,895,622 Sundin July 21, 1959 FOREIGNPATENTS 204,736 Austria Aug. 10, 1959

